The sugarcane harvester has wide application worldwide in the mechanized harvesting of sugarcane. In many applications, the sugarcane farm is of relatively small size, particularly in the third world. With such a small size acreage and tightly spaced crops, maneuverability of the sugarcane harvester at the ends of the row becomes particularly important. This maneuverability is made even more critical by the use of a topper mechanism that extends substantially from the main frame of the harvester forward down the row to cut off the top of the sugarcane at an appropriate length to enable subsequent cutting and processing of the stalk. Because the topper mechanism extends significantly beyond the front of the harvester, the maneuverability of prior art sugarcane harvesters with fixed topper booms is extremely limited.
It has been proposed to have a sugarcane harvester with a topper mechanism that pivots with adjacent crop dividers to provide significantly increased maneuverability when approaching the beginning of a crop row. This has proved significantly advantageous in small acreage sugarcane plots and greatly increases the utility and usefulness of the sugarcane harvester. Such mechanism includes a single actuator mounted on the outboard section of the harvester to drive the pivot levers for the topper mechanism and the crop divider frame sections. This arrangement provides effective pivoting of the mechanism but has a difference in force applied depending upon the direction of the turn owing to the differential surface area in the hydraulic actuator used to power such devices. Furthermore, the actuator is on an outboard section that could be exposed to crop material.
Therefore, what is needed in the art is a mechanism that provides uniform steering, force, and protection of the steering elements.